• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.493-504
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• 2004

The history books of East Asia about astronomical phenomena have the more records of the solar eclipse frequently than any other ones. It is because traditionally, the solar eclipse moaned the fate of dynasty and the king's rule. The Sun, the biggest thing in the heaven symbolized the king, and the solar eclipse foresaw that the king had the problem in private including the body, and the country might suffer from difficulties in a great scale. So the king and all of the ministers used to gather to hold a ceremony named Gusikrye(구식례) which solar eclipse may pass safely. Consequently, kings always had concernments on collecting informations of solar eclipse. Inspite of importance of solar eclipse predictions, but at the beginning of the Choseon, the predictions of the solar eclipse didn't fit. King Sejong compiled the Chiljeongsan-naepion (칠정산내편) and the Chiljeongsan-oepyeon(칠정산외편) to calculate the celestial phenomena including the solar eclipse. By the publications of these two books, the calendar making system of Choseon was firmly established. The Chiljeongsan-oepyeon adopted Huihui calendar(회회력) of Arabia. The Solar eclipse predictions of Chiljeongsan-oepyeon were relative correct compared to modern method in early Choseon dynasty.

• Journal of Conservation Science
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• v.36 no.2
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• pp.93-102
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• 2020

A lichen is a complex microorganism comprising fungi and algae. Various lichens are commonly found in cultural heritage and are reportedly related to weathering. Lichens are commonly studied in Europe; however, few reports exist on lichens in Korean cultural heritage. The present study was conducted as part of the Korean National Arboretum's "A study on the Fungus and Lichen." We report the lichen diversity found at the Placenta Chambers of King Sejong's Sons, Seongju. A total of 65 lichens were collected from 19 placenta chambers and one memorial stone. We identified 40 species belonging to 10 genera, 17 families, and 23 orders. Morphological identification revealed that foliose lichens in the form of leaves(24, 36.9%) and crustose lichens in the form of crust(24, 36.9%) were distributed at a higher percentage than that of fruticose lichen in the form of branches(17, 26.2%). Xanthoparmelia coreana(foliose lichen) and Lepraria sp.(crustose lichen) were the most collected lichens and were distributed on 19 chambers. In addition, Clodonia, a fruticose lichen, had the highest species diversity with eight species. The highest species diversity of lichens was identified on the chamber of Prince Kyeyang(16 lichens), whereas the chamber of Prince Geumsung had the lowest species diversity(five lichens). This study will be used as primary data for the study of distribution of lichen diversity in Korean cultural heritage.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.5-12
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• 2009

Soil samples from the King Sejong Station in Antarctic and Vladivostok were tested in the laboratory and specific gravity, compaction curve, grain size distribution were determined. The effect of temperature change on the thermal conductivity, unfrozen water content, compressive strength were investigated. In addition, the change of tensile strength with temperature of the soil from Vladivostok was measured. Samples for the compressive strength test and tensional strength test were prepared in a mould with a fixed volume to prevent swelling. Also the effects of temperature and water content change on those strength were compared. Results from the thermal conductivity test showed that thermal conductivity values for both soils was larger at temperatures below freezing than those above freezing. The unfrozen water content dropped rapidly within a temperature range of $0{\sim}-5^{\circ}C$ and then gradually decreased further $-20^{\circ}C$. Compressive strength test results showed various stress/deformation curves with a change in water content. Sandy soil of the King Sejong Station had a much larger strength than ice at an identical temperature, while clayey soil of Vladivostok had a smaller strength than ice in the initial stage, but showed a larger strength at temperatures belows $-15^{\circ}C$. Tensile strength tests revealed an increase in the strength with a decreasing temperature.

• Journal of the Korean Geophysical Society
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• v.8 no.3
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• pp.159-167
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• 2005

Turbulent fluxes of sensible heat and latent heat were analyzed at King Sejong station in the austral summer of 2002 (December) and 2003 (January and February). Monthly mean air temperatures of January and February (2.2oC) were similar to those averaged over 1988 to 2001. Precipitation was less in January and greater in February than those averaged over last 14 years. In December of 2002 and January, there was precipitation primarily when easterly wind blew usually. The frequency of snowfall was equal to or larger than that of rainfall. In the mean while, precipitation primarily in forms of rainfall occurred with westerly wind in February. In addition, while for easterly wind, temperature and humidity was low, temperature and humidity were high in case of westerly wind. Based on flux footprint, measured flux mainly came from within 300 m with maximum of 40 m upwind, indicating the insignificant role of the sea around the study site. Half-hourly downward short wave radiation amounted up to ∼ 1000 Wm-2 and net radiation ranged from -50 to 600 Wm-2. Half-hourly sensible heat flux was positive at daytime with maximum of ∼ 400 Wm-2, except the 27th and 28th in February of 2003 when it was negative all day despite of positive net radiation at short daytime. Latent heat flux was positive with maximum of ∼ 130 Wm-2. Depending on wind direction, the partitioning of net radiation into the sum of sensible heat flux and latent heat flux was larger than 0.8, indicating the strong source of the land surface for the atmospheric heating. The daytime averaged Bowen ratio (=sensible heat flux /latent heat flux) was significantly greater than 1, indicating that sensible heat flux was the main source to heat the atmosphere over the site.

• Tunnel and Underground Space
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• v.25 no.2
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• pp.199-209
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• 2015

The rebound hardness test using the SilverSchmidt hammer was performed for diorite, granodiorite, and andesite exposed around the King Sejong Station, Barton peninsula. Then, the R-value and uniaxial compressive strength (UCS) of these rocks were estimated from the Q-values which were obtained from the SilverSchmidt hammer. The Q-value of diorite was distributed in the range from 67.0 to 89.5, granodiorite of the range from 57.5 to 89.0, and andesite of the range from 58.0 to 76.5. The average Q-values of diorite, granodiorite, and andesite were 76.0, 72.0, and 67.0, respectively. The converted UCS of diorite was distributed in the range from 118 to 195 MPa, granodiorite of the range from 91 to 193 MPa, and andesite of the range from 92 to 148 MPa. The average UCS of diorite, granodiorite, and andesite were 147, 136, and 117 MPa, respectively. The converted R-value of diorite was distributed in the range from 53.0 to 72.2, granodiorite of the range from 45.4 to 71.8, and andesite of the range from 45.8 to 60.9. The average Q-values of diorite, granodiorite, and andesite were 60.0, 58.0, and 53.0, respectively. The R-value was represented approximately 20% lower than the Q-value. In conclusion, it will be possibile that the R-value and UCS of rocks under the extreme area from the SilverSchmidt Q-value are evaluated.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.123-130
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• 1980

Thiamine derivatives of thiamine tetrahydrofurfuryl disulfide (TTFD) and thiamine propyl disulfide (TPD) were obtained in a good yield and purity by use of thiothiamine $(SB_1)$ and also described in details for the preparing sodium tetrahydrofurfuryl thiosulphate (Bunte's salt) with and without KI. The optimum reaction conditions for the preparation of TTFD was set in which the Box-Wilson plan was applied. The reaction conditions are as follows; 1. pH value of aqueous solution of thiol type of $B_1{\cdot}HCl;12.09$ 2. Quantity of Bunte's salt (to $B_1{\cdot}HCl\;20G$); 35.01g 3. Reaction temperature; $15.59^{\circ}C$ Studies on ultraviolet absorption were made at various pH and showed that the absorption maxima are shifted with change of pH. The absorption maxima are at $244{\sim}246nm,\;234{\sim}235nm$ in TTFD, and $245{\sim}246nm,\;233{\sim}235nm$ in TPD. The structure was proved by the infrared spectral evidence. Quantitative determination was studied.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.517-523
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• 2017

A linear relationship between two stable water isotopes, oxygen and hydrogen, has been used to understand the water cycle as a basic tool. A slope and intercept from the linear relationship indicates what kind of physical processes occur during movement of water. Traditionally, ordinary least squares (OLS) method has been utilized for the linear relationship, but total least squares (TLS) method provides more accurate slope and intercept theoretically because isotopic compositions of both oxygen and hydrogen have uncertainties. In this work, OLS and TLS were compared with isotopic compositions of snow and snowmelt collected from the King Sejong Station, Antarctica and isotopic compositions of water vapor observed by Lee et al. (2013) in the western part of Korea. The slopes from the linear relationship of isotopic compositions of snow and snowmelt at the King Sejong Station were estimated to be 7.00 (OLS) and 7.16(TLS) and the slopes of stable water vapor isotopes were 7.75(OLS) and 7.87(TLS). There was a melting process in the snow near the King Sejong Station and the water vapor was directly transported from the ocean to the study area based on the slope calculations. There is no significant difference in two slopes to interpret the physical processes. However, it is necessary to evaluate the slope differences from the two methods for studies for example, groundwater recharge processes, using the absolute slope values.

• Korean Journal of Food Science and Technology
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• v.18 no.1
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• pp.55-60
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• 1986

The effects of temperature (70-$100^{\circ}C$), pH (3-8) and various sugars were investigated on the reaction rate, activation energy and z-value of Maillard reaction of 0.8m sugar and 0.8m glycine mixture. The sugars compared were glucose, fructose, lactose and sucrose, and the reaction was evaluated by absorbances at 278nm for pyrazine compounds and at 400nm for brown pigments. Fructose-glycine mixture showed a faster initial reaction rate than that of glucose-glycine, which was reversed by the order of glucose > fructose > lactose > sucrose after 10 hrs of reaction at pH 5.8 and $100^{\circ}C$. Generally, higher activation energy was required for forming pyrazines than that of brown pigment development. The highest z-value was obtained for lactose-glycine mixture, followed by glucose or fructose-glycine which had almost same z-value. The reaction rate was little affected by the pH change in the range of 4-6, while pH < 3 and pH 6-8 caused a significant increase in the rates.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.865-870
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• 1990

Four different fermentation methods of Korean cucumber pickles were compared with conventional method, pickling in 10% NaCl solution at $25^{\circ}C$, in order to improve the storage stability. The methods studied were brining the cucumbers in hot($90^{\circ}C$) 10% NaCl solution(method A), addition of KCl and $CaCl_2$ into the hot salt solution(method B) addition of a sodium salts mixture of phosphates, nitrite and citrate into half fermented pickles prepared by method B(method C), substituted nitrite and citrate with KCl in method C(method D). It was found from results that the method C and D reduced the decreasing rate of pH very significantly by more than 3 fold and method B also showed the reducing effect. However, higher total acidity was measured for method C and D, which was opposite to pH results. Changes in hardness of cucumber showed little difference to control while color of brining solution exhibited some difference in their Hunter values. Organoleptic comparison showed a clear effect of salts mixtures by receiving the significant higher scores in fresh cucumber flavor and lower values in yeast moldy and sour flavor for method C and D when those were compared to control.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.100-108
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• 1989

A study relating the sugar contents of radishes to the final titratable acidities(TA) after complete fermentation was conducted to get an idea of selecting radish varieties to improve storage stabilities of fermented pickled radish cubes. Thirty six varieties of spring-sowing and thirty four varieties of autumn-sowing radishes were chosen to ferment to measure their final TA in relation to their sugar contents. The sugar contents of spring-sowing radishes were in the range from 2.40 to $3.71^{\circ}\;Brix$ and the final TA ranged from 1.15 to 1.65%. The sugar contents of autumn-sowing radishes were in the range from 4.00 to $5.53^{\circ}\;Brix$ and the final TA ranged from 1.45 to 2.00%. The final TA obtained after complete fermentation were found to be directly proportional to the sugar contents of radishes, showing that TA equals to 0.29x+0.4428, where x is sugar content of radish. From the equation, since a properly aged fermented pickled vegetable is believed to have a TA range from 0.6 to 0.8%, a radish of a sugar content ranging from 0.6 to $1.3^{\circ}\;Brix$ will make fermented pickled radish cubes which will not be overacidified during the prolonged storage period.